Flats Sequencing System (FSS) is an automated system used by the

US Postal Service The United States Postal Service (USPS), also known as the Post Office, U.S. Mail, or simply the Postal Service, is an independent agency of the executive branch of the United States federal government responsible for providing postal serv ...

. It uses a dual pass sort technique to sort

flats Flat or flats may refer to: Architecture * Apartment, known as a flat in the United Kingdom, Ireland, and other Commonwealth countries Arts and entertainment * Flat (music), a symbol () which denotes a lower pitch * Flat (soldier), a two-dimens ...

all the way to delivery sequence order. Prior to the deployment of FSS machines, flats were machine sorted to the route level only. Carriers had to manually sort all the flats they were to deliver into proper delivery order before they could embark on their routes. With FSS, when the carrier receives them they are ready to be delivered without need for any further manual sorting. FSS machines are manufactured by

Northrop Grumman Northrop Grumman Corporation is an American multinational Aerospace manufacturer, aerospace and Arms industry, defense company. With 97,000 employees and an annual revenue in excess of $40 billion, it is one of the world's largest Arms industry ...

. Deployment began in 2008.

External links

Promotional video done in the style of a movie trailer
Mail sorting United States Postal Service {{Postal-stub